Large enough that it could almost have formed the nucleus of a protostar in its own right, Jupiter’s massive size makes the Jovian System one of the most challenging places in the system to colonize. Jupiter’s powerful magnetic field means that its inner moons— and the outer ones, when their orbits pass through its immense magnetotail—are bombarded with enough ionizing radiation to kill transhumans not protected by the heaviest of shielding within a matter of hours. There are sixty-three moons and moonlets in the Jovian system, but only the well-explored, populous, regular moons are described here.

Resources and economy

Jupiter’s powerful gravity well is a major hindrance to gas mining in the planet’s atmosphere, as even craft that do not succumb to the violent, centuries-long atmospheric storms can achieve escape velocity with only the most powerful propulsion systems. Given the need for heavy shielding on such craft, gas mining on Jupiter is not nearly as efficient as on Saturn. Jupiter has a tenuous ring system, much less dense than Saturn’s, which extends out for 20,000 kilometers around the planet, encompassing the orbits of its two closest moonlets.

However, Jupiter’s gravity is also a valuable resource. Craft bound for Saturn and beyond can slingshot themselves outward by circling the planet to pick up velocity, cutting months or years off their trips. The heavily militarized Jovian Republic levies tolls against all spacecraft using Jupiter’s gravity to pick up velocity, including asteroids under propulsion. This protection money is the Junta’s primary source of revenue. Planetary Consortium ships generally accept the payment as part of operating expenses. Other factions are not so cooperative, and the Junta regularly seizes or destroys blockade runners.

Habitats and moonlets

Most of Jupiter’s moons are really captured asteroids, lacking the size and geological complexity of planetary bodies. All are occupied. Some were converted to habitats; others host only Junta military and mining outposts. The Jovian moonlets consist mostly of carbonaceous rock, poor in metal, with some of the larger moonlets having layers or even cores of ice. Beehive habitats and Reagan cylinders predominate in the Jovian system. Reagan cylinders (called “sarcophagus habs” by every other faction) are an inefficient variation on the O’Neill cylinder in which excavators hollow out an immense, cylindrical cavern in a rocky asteroid and then alter the asteroid’s rotation with external thrusters to simulate gravity.

Other habitat types are rare in Jovian orbit, especially within 2 million kilometers of the planet, where the radiation is strongest. For a bioconservative faction unwilling to adopt radiation-resistant morphs, the Junta is in a poor location. Shielding their populace beneath tons of rock is a necessity. Despite its military hegemony, the Junta can’t control all of Jovian space, and there are things it can’t do on its own—like exploring Europa. A number of unaligned habitats and surface settlements exist in the ring system and the orbits of the Galilean moons.
The Jovian Republic has renamed Jupiter’s moons after various neo-conservative heroes from Earth’s history. From closest to most distant, the moonlets are Metis (Bush), Adrastea (Fairway), Amalthea (Solano), Thebe (McAllen), Leda (Chung), Himalia (Pinochet), Lysithea (Friedman), Elara (Buckley), Ananke (Nixon), Carme (Kissinger), Pasiphae (Schilling), and Sinope (Garcia). All are tiny, between 5 and 100 kilometers in diameter.

Amalthea (Solano)

The largest of the moonlets, hollow Amalthea is probably the most livable sarcophagus habitat due to the large lake created from its icy core. Living on Solano carries some prestige among Junta citizens. Rumor has it that most of the residents are well-placed RAND think tank personnel, most of whom work on defense projects. A fusion-powered axial light tube illuminates the 30-kilometer diameter central cavern, whose landscape is patterned after the subdivisions and office parks of an early 21st-century suburb. All buildings have envirosealing so that the occasional bouts of environmental sepsis resulting from the poorly regulated interior ecosystem can be purged with toxin bombs. Less fortunate support personnel dwell in the beehive warrens crisscrossing the moonlet’s crust between cavern and surface. Like most of Jupiter’s moonlets, Amalthea’s space crawls with patrol craft and killsats, making approach for unauthorized craft problematic at best. 1.5 million transhumans live on Solano.


Beneath Io’s tenuous, patchy atmosphere of volcanic gases and neutral atomic dust lies a barren, grayish yellow, rocky surface coated with a thin frost of sulfur dioxide. Tidal heating caused by gravitational interaction with Jupiter makes Io the most volcanically active body in the system—so active that the meteor cratering found on every other planet and moon is completely absent on Io. Massive volcanic calderas, lakes of molten rock, and geysers of sulfur dot the surface, with eruptions and accompanying seismic activity lasting months or years. Volcanic zones on Io reach surface temperatures of up to 1,500 degrees Kelvin, hotter than any body in the system.

For all that, transhumanity’s worst peril on Io is radiation. Ejecta from geysers and volcanoes flow with Jupiter’s magnetic field to form a titanic, toroidal flux tube that rotates with Io around the gas giant. Travelers to Io must either use the heaviest radiation shielding available or resleeve into synthetic morphs.

Transhuman activity on Io centers around scientific research and harvesting the volatiles ejected by Io’s geysers, particularly sulfur. Bases tend to be modular and mobile due to the ever-changing seismic activity. The Junta’s most notorious prison, Maui Patera Rehabilitation Center, is dug into a (mostly) extinct caldera wall north of the equator.


Beyond the Black questionable